Over the years, Ugartechea, as well as many other Basque gunmakers, imported guns into the US through many different dealers. I am pretty sure that American Import is out of business. But the importer is a non-issue. All that matters is the gun, and in general, Uggies are just fine.
Like many of the Basque makers, Ugartechea has made excellent guns, and has made some that aren't so nice. IIRC, Terry Weiland recounted in his book "Spanish Best" being taken to task for having referred to Ugartechea as a "Maker of Cheap Boxlocks." What followed was a nice education on the company and their guns.
Current Uggies are probably the best bang for the buck from the Basque gunmakers, and for classic English styled game guns, probably the best bang for the buck from any maker in the world. Their current offerings range from a simple but very servicable boxlock up to very nice round body sidelock with full coverage rose and scroll engraving.
Post a picture and I may be able to provide some more info.
Scott